Air conditioning systems for building structures, dwellings or individual rooms have historically utilized a standard vapor compression cooling system to cool an interior volume of a building structure 2 containing walls 4 and/or ceilings 6. A traditional home or building air conditioning system is shown schematically in FIG. 1. As shown there, the air conditioning system 10 typically includes an exterior positioned machine compartment housing 12 mounted on a base platform 14 where the housing 12 contains a single outlet, single input compressor 16, a condenser 18, and a thermal expansion device 20. These traditional systems also typically include a fan 22 associated with condenser 18, the size of which depends on various factors. For whole dwelling/building systems, which the compressor and condenser must provide higher cooling capacity, the systems are sized to match thermal load and are typically larger. Coolant fluid conduits 24 deliver coolant through the vapor compression system and deliver coolant fluid that has passed through the compressor, the condenser and the throttling device to a single evaporator 26 that operates at a single evaporator pressure located within an air passageway 28 within the building structure 2. The air passageway could be an air duct, air vents of a room air conditioning system or a portion of the building's interior heating, ventilation and air conditioning machine compartment located within the building structure 2. Typically, the evaporator 26 is positioned within the building's heating ventilation and air conditioning machine compartment. The air passageway 28 typically has an air circulation fan 30 associated with it to distribute air through the building structure 2 or into a portion of the building structure. The air circulation fan delivers air across the single evaporator where it is cooled and the cooled air 32 distributed to the volume of interior air to be cooled. Air is returned to the evaporator as shown by reference numeral 34. Typically, a building structure may have an exterior air inlet/path that allows exterior air to enter, typically passively enter, the building structure from outside the building structure either directly into the air passageway 28 or into the building structure air where the exterior air is then circulated within the building structure.
While this system does cool the building structure interior it typically does not allow for regulation of both the temperature and humidity of the interior of a building structure. When this traditional air conditioner is used, humidity is removed based upon the temperature of the single evaporator. A person within the interior volume of the building structure might want more or less humidity removed from the air within the building structure than what is allowed by such single evaporator systems.